Abstracts

The
interactions between plants and their animal pollinators and seed dispersers
have molded much of Earth’s biodiversity. Recently, it
has been shown that these mutually beneficial interactions form complex
networks with a well-defined architecture that may contribute to biodiversity
persistence. Little is known, however, about which ecological,
evolutionary, and coevolutionary mechanisms contribute to generate these
network patterns. Employing phylogenetic comparative statistical
tools, here we show that the evolutionary history of plants and
animals significantly predicts the number of interactions per species,
and the identity of the species with whom they interact. As a consequence
of phylogenetic resemblance on interaction patterns, simulated extinction
events tend to trigger coextinction cascades across related species. This
results on a non-random pruning of the evolutionary tree and a more
pronounced loss of taxonomic diversity than expected in the absence of
phylogenetic signal. Our results emphasize how the simultaneous consideration
of phylogenetic information and network architecture can contribute to
the conservation of species rich communities.

Photo: A plant-frugivore interaction network
in SE Spain (Cazorla). Frugivore species are depicted by red
nodes; plants are green nodes. Links between them represent the
interactions. The phylogenies of the two sets of species are depicted.
Phlogenetically-related species tend to show similar interaction
patterns; this might cause co-extinction cascades after extinction
of a mutualistic partner.